Move StringPiece into the base namespace. It is colliding

base/data_pack_unittest.cc

 // Copyright (c) 2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/data_pack.h"
 
 #include "base/file_path.h"
 #include "base/path_service.h"
 #include "base/string_piece.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 class DataPackTest : public testing::Test {
  public:
   DataPackTest() {
     PathService::Get(base::DIR_SOURCE_ROOT, &data_path_);
     data_path_ = data_path_.Append(
         FILE_PATH_LITERAL("base/data/data_pack_unittest/sample.pak"));
   }
 
   FilePath data_path_;
 };
 
 TEST_F(DataPackTest, Load) {
   base::DataPack pack;
   ASSERT_TRUE(pack.Load(data_path_));
 
-  StringPiece data;
+  base::StringPiece data;
   ASSERT_TRUE(pack.Get(4, &data));
   EXPECT_EQ("this is id 4", data);
   ASSERT_TRUE(pack.Get(6, &data));
   EXPECT_EQ("this is id 6", data);
 
   // Try reading zero-length data blobs, just in case.
   ASSERT_TRUE(pack.Get(1, &data));
   EXPECT_EQ(0U, data.length());
   ASSERT_TRUE(pack.Get(10, &data));
   EXPECT_EQ(0U, data.length());
 
   // Try looking up an invalid key.
   ASSERT_FALSE(pack.Get(140, &data));
 }